Amd Zen µcode not loading ?

Moonboots · Apprentice Joined: 02 Dec 2006 Posts: 161

With frequent motherboard bios updates for the Asus 350M-A , i have relied on those for any potential ucode updates.
But with "Spectre" bug i decided to update via the kernel following the instructions on https://wiki.gentoo.org/wiki/AMD_microcode by adding amd-ucode/microcode_amd.bin amd-ucode/microcode_amd_fam17h.bin to the end of list of amdgpu firmware entries. But on rebooting and regarding dmesg i don't see any update and the patch_level is as before ?
My cpu is a Ryzen 1700 and https://wiki.gentoo.org/wiki/Project:Security/Vulnerabilities/Meltdown_and_Spectre mentions "A CPU microcode update was added which will disables branch prediction on AMD family 17h processors (800F12 only)"
I haven't been able to find what 800F12 corresponds to ?

Any help would br gratefully received

NeddySeagoon · Posted: Sat Jan 06, 2018 8:52 pm Post subject:

Moonboots,

You also need

Moonboots · Apprentice Joined: 02 Dec 2006 Posts: 161

NeddySeagoon

Thank you , but CONFIG_MICROCODE_AMD=y is already in my kernel by selecting "AMD microcode patch loading support" from https://wiki.gentoo.org/wiki/AMD_microcode

I'm booting from efi stub kernel without Initramfs , if that is potentially a problem ?

NeddySeagoon · Posted: Sat Jan 06, 2018 9:59 pm Post subject:

Moonboots,

I have my microcode built into the kernel as that wiki page suggests.
I have an initrd too for raid and LVM but its strictly user space tools from 2009.
In short its not a problem.

Did you check that you are running the kernel you think you are?

marcuse · n00b Joined: 17 Jan 2003 Posts: 25

This doesn't work for me too, but as metioned here https://wiki.gentoo.org/wiki/Project:Security/Vulnerabilities/Meltdown_and_Spectre#sys-kernel.2Fgentoo-sources, the actual firmware is only for:

thumper · Guru Joined: 06 Dec 2002 Posts: 552 Location: Venice FL

I had the same apparent failed results.

But then I saw this:
https://www.phoronix.com/scan.php?page=news_item&px=AMD-Branch-Prediction-Still

So now I'm not sure what to expect.

George

Naib · Posted: Sat Jan 06, 2018 11:32 pm Post subject:

AMD have stated they do not rely on a bios update to deal with spectre mitigation. I'll find the link

https://lkml.org/lkml/2018/1/5/383
https://lkml.org/lkml/2018/1/5/405
_________________

Moonboots · Apprentice Joined: 02 Dec 2006 Posts: 161

Thanks everyone

Yes Neddy i was running the expected kernel.

@marcuse @thumper Hopefully there will be more information on this µcode update in the coming days.

@Naib There is a gatewaytime-out on both links at the moment, so i'll try later on.

Moonboots · Apprentice Joined: 02 Dec 2006 Posts: 161

Looks like we may see a microcode update for Ryzen soon ?

https://www.amd.com/en/corporate/speculative-execution